Watershed morphometric analysis of a basin is key to understand the hydrological processes. The Gilgit river basin is situated in the Hindu Kush and Karakoram Mountains of Pakistan. The provincial capital of Gilgit-Ba...Watershed morphometric analysis of a basin is key to understand the hydrological processes. The Gilgit river basin is situated in the Hindu Kush and Karakoram Mountains of Pakistan. The provincial capital of Gilgit-Baltistan is located in the lower part of the basin. Morphometric evaluation of the Gilgit river basin was carried out to study its drainage characteristics and overall water resource potential. The entire Gilgit river basin has been divided into six sub-basins to calculate and analyze the selected morphometric parameters. Morphometric parameters have been classified into linear, aerial and relief aspect. Geographic Information System (GIS) provides a viable method to extract and evaluate the characteristic of hydrological response behaviour of the basin. In the present study the utilization of remote sensing data such as Thermal Topography Mission and Global Elevation Model (ASTER-GDEM), Sentinel 2A image, coupled with geological and field data into GIS environment for morphometric analysis of Gilgit Basin. The drainage area of the basin is 13,538 km2 and shows a dendritic drainage pattern for all sub-basins. The analysis reveals that drainage network of entire Gilgit river basin constitutes a 7th order basin. Out of six sub-basins, Gilgit-Gahkuch (B1), Ishkoman (B2) and Phunder (B4) are 6th order sub-basins. Yasin (B3) and Gupis (B5) are 5th order sub-basins, while Bagrot (B6) is a 4th order sub-basin. The Gilgit Basin drainage density value is 0.50 km/km2, which indicates a well-drained basin. Morphometric parameters like stream number, order, length, bifurcation ratio, drainage density, stream frequency, elongation ratio, circularity ratio, form factor, relief and relative relief, slope, length of overland flow, ruggedness number, and hypsometric integral are calculated. The results indicate that the entire drainage basin area reflects youthful to early mature stage of the fluvial geomorphic cycle and high potential of stream discharge which is dominated by high relief, rainfall, glacier and snow fed order streams.展开更多
The South Asia has high variability in geographical features,climate,andlandscapes.With the rapid economic development and population growth,the increased pressure on natural resources,land degradation,water crisis,an...The South Asia has high variability in geographical features,climate,andlandscapes.With the rapid economic development and population growth,the increased pressure on natural resources,land degradation,water crisis,and climate change become the common concerns forthe countries in the region.To get a deep and general idea about the land and water natural resources and environment in South Asia,a knowl-edge database was constructed based on the climatic condition,land use/cover,waterresources,water disasters,and geohazards.There sults presented a scientific insight regarding the spatio-temporal changing pattern of the eco-environ mental components in this region.Risk assessments were performed for the floods,droughts,and geohazards which occurred with a high frequency.In general,the big knowledge database established in this study would be helpful to aid the devel-opment of future policies and programs(like the Belt and Road Initiative)for environmental issues adaptation in the region,including initiatives for regional cooperation and capacity building in natural resources and environment management.展开更多
文摘Watershed morphometric analysis of a basin is key to understand the hydrological processes. The Gilgit river basin is situated in the Hindu Kush and Karakoram Mountains of Pakistan. The provincial capital of Gilgit-Baltistan is located in the lower part of the basin. Morphometric evaluation of the Gilgit river basin was carried out to study its drainage characteristics and overall water resource potential. The entire Gilgit river basin has been divided into six sub-basins to calculate and analyze the selected morphometric parameters. Morphometric parameters have been classified into linear, aerial and relief aspect. Geographic Information System (GIS) provides a viable method to extract and evaluate the characteristic of hydrological response behaviour of the basin. In the present study the utilization of remote sensing data such as Thermal Topography Mission and Global Elevation Model (ASTER-GDEM), Sentinel 2A image, coupled with geological and field data into GIS environment for morphometric analysis of Gilgit Basin. The drainage area of the basin is 13,538 km2 and shows a dendritic drainage pattern for all sub-basins. The analysis reveals that drainage network of entire Gilgit river basin constitutes a 7th order basin. Out of six sub-basins, Gilgit-Gahkuch (B1), Ishkoman (B2) and Phunder (B4) are 6th order sub-basins. Yasin (B3) and Gupis (B5) are 5th order sub-basins, while Bagrot (B6) is a 4th order sub-basin. The Gilgit Basin drainage density value is 0.50 km/km2, which indicates a well-drained basin. Morphometric parameters like stream number, order, length, bifurcation ratio, drainage density, stream frequency, elongation ratio, circularity ratio, form factor, relief and relative relief, slope, length of overland flow, ruggedness number, and hypsometric integral are calculated. The results indicate that the entire drainage basin area reflects youthful to early mature stage of the fluvial geomorphic cycle and high potential of stream discharge which is dominated by high relief, rainfall, glacier and snow fed order streams.
基金This work was jointly supported by the Strategic Priority Research Program“Big Earth Data Science Engineering Project”(CASEarth)[No.XDA19030303]the Key Program(KZZD-EW-08-01)of Chinese Academy of Sciences,the International Cooperation Key Project of CAS[No.GJHZ201320]+2 种基金the National Natural Science Foundation of China[No.41631180]the 135 Strategic Program of the Institute of Mountain Hazards and Environment,CAS under Grant SDS-135-1708the Youth Innovation Promotion Association CAS[Grant 2016333].
文摘The South Asia has high variability in geographical features,climate,andlandscapes.With the rapid economic development and population growth,the increased pressure on natural resources,land degradation,water crisis,and climate change become the common concerns forthe countries in the region.To get a deep and general idea about the land and water natural resources and environment in South Asia,a knowl-edge database was constructed based on the climatic condition,land use/cover,waterresources,water disasters,and geohazards.There sults presented a scientific insight regarding the spatio-temporal changing pattern of the eco-environ mental components in this region.Risk assessments were performed for the floods,droughts,and geohazards which occurred with a high frequency.In general,the big knowledge database established in this study would be helpful to aid the devel-opment of future policies and programs(like the Belt and Road Initiative)for environmental issues adaptation in the region,including initiatives for regional cooperation and capacity building in natural resources and environment management.
